The era of personalized medicine is emerging as physicians attempt to diagnose disease in asymptomatic individuals and treat pathology early in its natural history. A novel tool in an emerging armamentarium, molecular imaging will allow noninvasive characterization and segmentation of patients for delivering custom-tailored therapy. Nanoparticulate agents, such as superparamagnetic agents, liposomes, perfluorocarbon nanoparticle emulsions, and dendrimers, are being intensively researched as formulation platforms for various targeted clinical applications. As exemplified by perfluorocarbon nanoparticles, these new agents, in combination with the rapid innovations in imaging hardware and software, will allow the emergence of new medical diagnostic and therapeutic paradigms.